Top stories from the 18th CROI conference

CROIthe Conference on Retroviruses and Opportunistic Infections – is one of the main science and medical conferences on HIV.

The conference is named how it is because HIV is a retrovirus(meaning it has to re-write its genome backwards before it can stick the genome into a cell’s own DNA). Opportunistic infections are conditions that do not typically arise in health people, but sometimes occur when someone’s immune system is not behaving correctly because of HIV/AIDS. CROI rhymes with “boy” and not the French word “crois”, meaning “believe”, as I once wondered when I was newly studying HIV.

It’s held every year, and this year it was in Boston. There were over 4000 people who attended the conference, both to present their own research and learn about new cutting-edge studies that have happened in the field in the past year.

The weather was mostly pretty cooperative, but wow did it get cold towards the end there – especially for a Vancouver boy. The conference consists of a number of oral presentations, as well as poster presentations (I had a poster there – number 668 if you’re curious).

The whole conference can be viewed online at the conference website.

For those who don’t know, when you apply to a conference you submit what’s known as an abstract. Abstracts are short blurbs that summarise the research you did and why it’s important. Then the conference committee can either reject your abstract, or accept it as an oral presentation or poster. There were a total of 1024 abstracts accepted out of around 2000 submitted. So I DEFINITELY won’t be able to cover everything, but I’m going to just quickly touch on some of the talks I found most interesting.

CROI YouthCO Issues

This year’s CROI was very relevant to the issues YouthCO is most involved with. First, obviously there was a great deal of research presented on HIV. But there were also probably around 50 oral and poster presentations on Hep C, and probably around the same number on youth with HIV, including a whole themed discussion dedicated to antiretroviral therapy in youth (session 14).

I’m going to try to link directly to the video from any of the presentations that I talk about here (the links are in the titles), but in case the links fall through, you can always search the website to find them, so I’ll give you the session numbers and abstract numbers to search.

Here are my top 5 picks from CROI 2011

1) ART Use and Outcomes among Youth

Session 14 – Abstracts 692 – 695.

This was a really interesting session on some of the specific needs that youth have for staying engaged in health care, and keeping healthy.

Obviously youth are not adults, and we need to be treated differently.

Allison Agwu and her colleagues presented about some of the factors that affect when youth start taking HAART, and when they stop it.

One of the big findings to me was that youth were over twice as likely to stop taking HAART if they were receiving their treatment at a site that specializes in adults instead of youth. This seems to indicate that adult clinics aren’t all giving youth the support they need to stay on treatment, which can be difficult for youth already dealing with issues of marginalization and stigma around their status.

2) Some possible reasons why coinfection of HIV with another virus can be a good thing

Session 7 – Abstracts 26 and 27

There’s a virus called GB virus C (GBV-C) which used to be called Hepatitus Virus G, and which is related to Hep C. For reasons that aren’t well understood, people who are infected with both HIV and GBV-C seem to actually have a slower course of their HIV disease.

This better outcome is kind of puzzling, so Molly Perkins and colleagues and Jack Stapleton and colleagues tried to figure out what is going on here. They had some conflicting results, but both seemed to find that certain cell types generally had fewer copies of that HIV coreceptor that keeps coming up called CCR5. Since most strains of HIV need CCR5 to get into a cell, having fewer of them makes infection more difficult for the virus. And having fewer copies of CCR5 on the cells could be caused by co-infection with GBV-C.

3) Advances in Hepatitis

Session 1 – Abstract 5

Every year just before CROI officially begins, they have a “Young Investigator Workshop”. At it, all of us young scientists, clinicians and community educators get a crash course in some hot topics that have emerged in HIV over the past year.

This year, one talk at the workshop was dedicated to Hep C treatment. This year has been an exciting time for the treatment of Hep C. There are new anti-Hep C drugs called telaprevir and boceprevir, which have almost completed advanced clinical trials, and the data look good.

Some people have trouble with Hep C treatment, which right now consists of two agents called pegylated inferferon-alpha and ribavirin (the “standard treatment”). Those agents are often hard to take for people because of side effects and don’t always result in “clearing” the Hep C virus from their bodies.

However, when you combine these drugs with the new Hep C drugs (which interfere with a crucial Hep C protein called protease), substantially more people actually get cured of Hep C than with the standard treatment by itself.

The coloured lines in the graph consist of different doses of boceprevir plus the standard treatment, versus just the standard treatment alone (shown in black). The lines show the percentage of patients who had undetectactable Hep C levels even out to 6 months after stopping treatment. Far more patients had undetectable Hep C 6 months after treatment if they also took boceprevir, compared to just the standard treatment alone.

Also significant is the fact that these new anti-Hep C agents seem to work pretty well for people who didn’t respond to the standard treatment, or who only had temporary responses to it. So that’s good news for people who have had trouble with Hep C treatment in the past.

4) Hep C treatment in people who also have HIV

Abstract 146LB

CROI also had the first presentation ever of early data for the new Hep C drug telaprevir in patients who have both HIV and Hep C.

Mark Sulkowski and colleagues presented that patients CAN receive anti-HIV treatment and new anti-Hep C treatment at the same time. There didn’t seem to be any safety issues with treating both at once, and more patients who took telaprevir achieved a cure of their Hep C compared to patients who took the standard treatment but not telaprevir.

Overall, that new drug seems to be safe and effective in treating Hep C even in patients who also have HIV and who are on HAART. Encouraging results, but larger studies are needed to make sure.

5) Disrupting the CCR5 coreceptor with zinc-finger nucleases

Session 47 – Abstracts 164 & 165

OK, so we talked last time about zinc finger nucleases. These are special molecular scissors that can target specific areas of the human genome and cut them up. Researchers are starting to use zinc finger nucleases (ZFNs) to target the HIV coreceptor, CCR5, and mess with it.

By treating a patient’s cells with ZFNs, disrupting the CCR5 gene in them, and putting those modified cells back in the patient, we may be able to make the patient’s immune system “resistant” to further infection.

At this year’s CROI, we got an update on some different ways people are trying to use ZFNs against CCR5 to genetically engineer a patient’s cells to prevent infection by HIV. There are early clinical trials of this approach and Carl June presented on one of them.

The idea of the trials is to treat patients who already have HIV, and modify their cells to block entry of the virus using ZFNs. The results are still very preliminary, but the modified cells seemed to stick around in patient’s bodies when they were injected back in, and importantly seemed to expand and make new cells that now lacked CCR5, and therefore lacked an entry point for HIV.

There didn’t seem to be any major safety issues with this approach seen so far, but longer follow-up is needed.  Just to show how up-to-the-moment this research is, Dr June presented on only 2 patients who had been followed for long enough to see any results.

These two patients had a treatment interruption (labelled “TI” in the graph on the right) where they stopped taking their anti-HIV medications for a pre-defined period of time.

There were some interesting results. Concentrate on the greyed out box in the graph. In one patient (the one shown in red), the HIV viral load took over two months to appear again after stopping anti-HIV treatment. This is far longer than is usually seen in people who stop taking HAART, and could be because there were fewer cells with CCR5 around for HIV to be able to infect and replicate in. And in both patients, the viral load started to go down during the treatment interruption, even though neither patient was taking therapy.

This could be because the cells that could support infection (the ones that still had CCR5) were being replaced by the ones that couldn’t be easily infected (the ZFN modified ones), so there were fewer cells pumping out virus during this time, so the viral load fell.

These are encouraging early results, but remember this is only two patients, and neither of them has been cured. I’m really looking forward to seeing how this potential treatment will work for more patients.

All in all…

Overall, CROI had a lot of research that was really relevant to things that YouthCO members are dealing with. I tried to highlight just a few of the over 1000 abstracts that were presented there, and there were a lot more that were really just as interesting and ground-breaking.

What kinds of research topics would YOU like to see at next year’s CROI? Were there any abstracts you came across that you’d like explained? Why not leave a comment below…

One Response to “Top stories from the 18th CROI conference”
  1. Teyshan says:

    Great stuff, thanks for the birds eye view of the conference! I think you should do a piece on HIV re-infection, as there seems to be a lot of confusion on this topic.

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